Conventionally, the following device provided with a plurality of transducers arranged in a single row are well known as a device for detecting a shape of a target object using an ultrasonic wave (for example, refer to JP1992-317641(A)). This conventional shape detection device transmits ultrasonic waves to a target object with the plurality of transducers sequentially from one end of the transducer row, and the same transducer receives a reflected wave from the surface of a target object. Because the distance from each transducer to the front surface of the target object differs, time after an ultrasonic wave is transmitted from each transducer until each transducer receives a reflected wave also differs. Thus, by using the difference in phase of the received wave signals of the reflected waves by the plurality of transducers (i.e., the difference in propagation time from wave transmission to wave reception), the shape of the target object can be detected.
Generally, a transducer is connected with a transmission circuit, and by receiving an electric signal from the transmission circuit, microscopically oscillates to generate an ultrasonic wave. In order to actuate the plurality of transducers in order, it is necessary to sequentially shift the transmission timing of an electric signal for each transducer from the previous one. Therefore, a wave-transmission module of the conventional shape detection device described above needs to be including a plurality of transmission circuits connected to the plurality of transducers, or including a change-over circuit for changing-over the transducer to be connected to the transmission circuit among the plurality of transducers. Therefore, the circuit configuration will be complicated and its cost will increase.
Further, because the conventional shape detection device described above drives the plurality of transducers in order and receives the reflected waves, it requires a certain amount of time for all the transducers to finish the wave transmission and wave reception of ultrasonic waves. Therefore, for example, if the object to be measured is a bone of a living body, the examinee may move while the measurement to lower the detection accuracy.